Process of obtaining potash from feldspar.



pnirnp STATES PATENT oFF o-E.

HARRY P. BASSETT, 0F GATONSVILLE, MARYLA ND, ASSIGNOR TO THE SPAR CHEMICAL COMPANY, OF BALTIMORE, MARYLAND, A CORPORATION OF MARYLAND.

PROCESS OF OBTAINING POTASH FROM FELDSPAR;

No Drawing.

of Obtaining Potash from Feldspar, of

which the following is a specification.

This invention relates to the production of potash and has particular reference to the recovery of potash fromfeldspathic and similar rock containing insoluble potash salts.

In the practice of my process in its preferred form the feldspathic or similar rock is first ground to pass through a one hundred mesh sieve. The powdered rock is then mixed with an alkali metal acid sulfate, an alkali metal chlorid and a reducing-agent preferably carbon in the form of coke and heated to a bright red heat. The materials are preferaby mixed in the following proportions by weight: feldspar 40 parts, sodium acid sulfate 40 parts, sodium cilorid 14.4 parts, coke 1 to 3 parts. While t e proportions stated yield the best results, the relative amount of carbon employed being of particular importance, I have found that some measure of success may be obtained by altering the proportions of the ingredients somewhat. It is to be understood,'however, that the proportion of carbon or carbonaceous matter cannot be materially increased without seriously-interfering with the practical operation of the process, since the reducing agent must be present in such proportion as to exercise a reducing action on' a considerable portion of the sodium acid sulfate during the early stage of the heating operation after which, but before the termination of suchheating operation the reducing agent is entirely consumed, thereby permitting ofthe oxidation of the resulting sodium sulfid to sodium sulfate. The heating is preferably carried on in the presence of air, the latter stage of the heating operation, wherein the sodium sulfid is transformed into sodium sulfate, requiring that oxygen be present to effect such oxidation.

While the reactions which takeplace are obscure and cannot be definitely stated it is believed that the reducing agent reduces a portion of the sodiuin acid sulfate to sodium sulfid during-the early stage of the heating operation and that such sodiumsulfid, act- Specification of Letters Patent.

Patented Mar. 24, 1914.

Application filed September 18,1912. Serial No. 720,959.

ing probably as a catalytic agent, coiiperates With the unchanged sodium acid sulfate and sodium chlorid to break up the feldspar molecule and'set the potash contained thereinfree in water soluble form. The sodium sulfid aftervserving its function as above indicated and after the carbonaceous matter is entirely consumed, is oxidized, during thelater stage of the heating operation into sodium sulfate in which form it appears in the products of the reaction.

The heating of the mixture above referred to is carried on at a bright red heat for preferably from oneto two hours, thefheating being continued until a specimen taken from the fused or partially fused mass is found to be free from sodium sulfid. The

mass is then allowed to cool and is leached covering potash from feldspar or similar The sodium and potassium materialcontaining potash in an insoluble form which consists in mixing the same with an alkali metal acid sulfate, an alkali metalv chlorid and a reducing agent, the reducing agent being employed in such quantity as to reduce only a part of the sulfate,heating the mixture and separating the soluble portion from the remaining portion of the resulting mixture. v

2. The herein described process covering potash from feldspar or similar material containing potash in an insoluble of reform which consists in mixing the same with an alkali metal acid sulfate, an alkali .metal chlorid and a reducing agent, the reducing agent being employed .in such quantity as to reduce only a part of the sulfate, heating themixture to a bright redheat for approximately from one to two hours, and separating the soluble portion from the remaining portion of the resulting mixture.

' 3; The herein described process of re covering potash from feldspar or, similar material containing potash in an insoluble form which consists in mixing the same with an alkali metal'acid sulfate,fan alkali -metal chlorid and a. reducing agent in the feldspathic rock, 40 parts of the alkali metal covering po'tashafrom feldspar or similar approximateproportions of 40 parts of sulfate, 14.4" parts of the alkali metal chlorid and 1 to 3 parts of the reducing agent, heating the mixture to a bright red heat and separating the soluble portion from the remaining portion of the resulting mixture. I v

'4. The 'herein described process of recovering potash from feldspar or similar material containing potash in an insoluble form which consists in mixing the same with sodium acid sulfate, sodium chlorid and carbon, heating the mixture, separating the sodium sulfate and potassium sulfate from the remaining portion of the fused mass and separating the sodium sulfate from the'potassium sulfate.

' 5. The herein described process of rematerial containing potash in an insoluble form which consists in mixing the same with sodium sulfate, sodium chlorid and carbon in the approximate proportions of 40 1 parts of feldspar, 40 parts of sodium acid 1 sulfate, 14.4 parts of sodium chlorid and 1, to 3 parts of carbon, heating the mixture to a bright red heat for approximately from one to two hours, separating the resulting potassium sulfate and sodium sulfate from the insoluble portion of the mass and separating the potassium sulfate from the sodium sulfate, substantially as described.

6. The process of recovering potash from materials containing an insoluble potassium compound which consists in heating a mixture thereof with sodium acid sulfate and sodium chlorid to approximately a bright red heat, in the presence of a reducing agent, the reducing agent being employed in such quantity as to reduce only a part of the sulfate and separating the Water soluble portion of the resulting mixture from the remaining portion thereof.

In testimony whereof I aflix my signature in presence of two witnesses.

HARRY P. BASSETT.

\Vitnesses HARRY E. GILBERT, JNo. M. Hanna-o.

Copies. this patent may be obtained for five cents each, by addressing the Commissioner of fatentl.

' Washington, D. C. 

